Editor’s note: To read Part I of this three-part article series, click here.

Conceding Israeli control of the 34-mile-wide area known as Judea and Samaria to any of Israel’s actual or even potential enemies means a return to the pre-1967 nine-mile waistline across Israel’s coastal strip and a security border of 223 miles to patrol and defend. Retention of said territories means a mere 62 miles of security border to patrol and defend. It also means Israeli control of vital mountain passes, the 4,200-foot high ground overlooking the Jordan Rift Valley, and the minimal strategic depth between the Jordan River and Israel’s highly populated and industrialized coastal plain.

To comprehend why this is so important to Israel’s security, it is necessary to understand the difference between Israel before mass mobilization and afterwards.

When Israel fights a war, it must take into account many factors: weapons technologies, tactical knowledge, motivation and education of the soldiers, etc. However, the prime factor is still numbers. The best equipped and most superiorly trained army cannot win if it is hopelessly outnumbered. This has always been an issue for Israel.

The IDF, as every responsible army, must be prepared for every eventuality. Israel cannot afford to lose a war. According to reports, the latest annual IDF General Staff exercises dealt with various combinations of possible attacks from different fronts including south (Gaza and Egypt), north (Lebanon and Syria) and east (Iran). Other possibilities were also taken into account, but those were the major ones.

In each of these possibilities, strategic depth is a critical factor. In the south, Israel has already given up its strategic buffer areas, and if the IDF were to fail to take the battle into enemy territory (basic IDF doctrine), the fighting would be within easy range of major Israeli population centers.

In the north, the Golan Heights are, as always, critical, and in the northeast and east, Judea and Samaria are not only vital for defense, but would also serve as passage ways for mobilization and logistics. (The Cross-Samarian Highway, for example, was originally planned by the IDF General Staff following the 1967 Six Day War as the major connecting artery to the Jordan Valley from the coastal plain.)

Despite the immense security risks Israel faces, the Jewish State’s small population means it doesn’t have the security of a large standing army despite the immense security risks it faces. For that reason, soldiers who have completed their mandatory service, continue in the reserves – especially in combat units – well into their forties, contributing up to over a month or more of service each year for both training and active-duty assignments. In short: the army reserves constitute the backbone of the IDF’s manpower needs.

IDF doctrine encompasses a number of basic security truths. Among them are that Israel cannot afford to lose a single war, we must have a credible deterrent posture including territorially, and that the outcome of war must be determined quickly and decisively. Proper preparation means Israel’s small standing army must be equipped with an early-warning capability, coupled with an efficient reserve mobilization and deployment system.

Israel, prior to mobilization, is basically a relatively weak country militarily in terms of all out war with more than one front involved – which is a distinct possibility that the IDF planners seriously take into account. Post-mobilization Israel, on the other hand, is an entirely different story.

Israel has the potential to mobilize hundreds of thousands of reserves which more than triples the manpower of the Israeli army. This considerably alters the ratio against the enemy. While exact figures are classified, suffice to say the combined Arab armies outnumber Israel’s standing army by a ratio of approximately 15 to 1. Whereas after a full scale call-up of Israel’s reserves, the ratio is reduced to less than 4 to 1.

While these are still great odds against the Jewish State, it is necessary to add into the mix the Israeli army’s strength: superior weapons systems, intelligence and logistics, better training, higher education and motivation (being in a “no alternative” situation where losing means national annihilation is a major factor in superior motivation). The result is an army with a better than even chance of winning a war.

As noted, current Israeli defense doctrine must take into account the vulnerability of its national infrastructure to enemy missile attack. This means reserves deployment locations must be sufficiently dispersed and distant from one another and from the border itself, to increase the chances of completing the mobilization and deploying the reserve forces to the war zone, even in the event of a missile attack. If the reserve mobilization were delayed by a barrage of ballistic missiles, then initial terrain conditions for Israel’s small, numerically inferior, standing army units would become all the more critical.

Judea and Samaria’s mountain ridge is also crucial to Israel’s air defenses. Israel deploys its air defense facilities along the mountain ridge to enable the interception of enemy aircraft from forward positions instead of from the heavily populated coastal plain. Short-range radar and early-warning systems situated in the coastal plain would have their line-of-sight blocked by the Judea and Samaria mountain ridge. Without control of this high ground Israel would have no warning time to intercept attacking aircraft. It takes only three minutes for an enemy fighter bomber to cross the Jordan River and fly the 42 miles to Tel Aviv. If Israel’s strategic depth were 34 miles less (i.e.: without Judea and Samaria), enemy planes could leave Arab air space and reach Tel Aviv in under one minute or less than minimum Israeli “scramble time,” not to mention ground defenses’ reaction time.

But to win the war with the aforementioned better than even chance, another agonizing problem must be solved. As noted, Israel requires 48 hours to fully mobilize. It is economically unfeasible for the IDF to be in a state of constant mobilization. The productivity of the country would grind to a standstill. No nation could survive such conditions indefinitely. In fact, it was due to this factor that the Soviet Union was able to orchestrate the 1967 Six Day War.

The Soviets informed the Egyptians that Israel was mobilizing on its northern borders opposite Syria. Although untrue, it caused the Egyptians to pull their troops out of Yemen and mass them on the Israeli lines. This in turn forced Israel to truly mobilize – this time opposite Egypt. Realizing the consequences of long-term mobilization, Israel sent word to Egypt proposing a mutual de-escalation of troops. Nasser’s response was to close the Straits of Tiran, which was an act of war. Israel, faced with the task of waiting for Egypt to attack, while forced to maintain an unending full-scale mobilization with the consequences of impending national economic disaster, had no choice but to act. Hence, Israel’s preemptive attack on the morning of June 5, 1967.

While conventional warfare, Israel’s main threat up until the late 1980s, subsequently became less probable, the threat of terrorist attacks together with missiles, from short-range rockets to large ballistic missiles, appear to have become the primary threats Israel faces. However, the political upheaval in the Arab world in the last few years cannot rule out – especially with the rise in prominence of radical Islamic elements in Syria, Jordan, Iraq and Egypt, among others – the potential return of regular Arab armies facing Israel in the near future.

Even in the missile age, wars are still ultimately decided by the movement of armies and not just by air strikes. As long as conventional ground forces remain the decisive element in determining the outcome of wars, then such issues as territory and strategic depth are crucial. Despite the proliferation of missiles and the use of terrorism as a strategic weapon, most of Israel’s Arab neighbors still stress the role of heavy armor in their order of battle, thus conventional warfare remains a significant potential threat.